AP Precalculus / Unit 2: Exponential and Logarithmic Functions
2.6 Competing Function Model Validation
Notes
Compare models by how well they match the data and by their residuals (actual − predicted).
- A good model has residuals scattered randomly around 0, with no pattern.
Practice
A residual plot shows a clear curved pattern. This suggests:
Patterns mean the model misses structure.
Actual value 42, predicted 45. The residual:
$42-45$.
Data with nearly constant ratios between consecutive outputs fit best with:
Constant ratios mean exponential.
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